• Ecology and Resilient Infrastructure
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• v.6 no.1
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• pp.1-11
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• 2019

This study performed the impact of ecological waterway on fish community in a reach of the Dal River, Korea. Fish monitoring revealed that 9 fish species are dominant, namely Zacco platypus, Coreoleuciscus splendidus, Zacco koreanus, Pungtungia herzi, Acheilognathus yamatsutae, Rhinogobius brunneus, Tanakia signifer, Gobiobotia macrocephala, and Pseudopungtungia tenuicorpus, and account for 95% of the total fish community. The River2D model was used for the computation of the flow and the HSI model for the habitat simulation. The restoration of the waterway performed through the small dam removal, the formation of the pool-riffle structure, and the change of the bed elevation and width. Simulation results indicated that the restoration of the ecological waterway effects significantly increased by about 16% for the WUA (Weighted Usable Area) of the total fish community in optimal ecological flow conditions ($Q=7.0m^3/s$). The restoration of the ecological waterway is more advantageous to fish community.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.112-118
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• 2009

Ammonia-oxidizing bacteria (AOB) are chemolithoautotrophs that play a key role in nitrogen removal from advanced wastewater treatment processes. Various AOB species inhabit and their community compositions vary over time in the wastewater treatment bioreactors. In this study, a hypothesis that operational and environmental conditions affect both the community compositions and the diversity of AOB in the bioreactors was proposed. To verify the hypothesis, the clone libraries based on ammonia monooxygenase subunit A were constructed using activated sludge samples from aerobic bioreactors at the Pohang, the Palo Alto, the Nine Springs, and the Marshall wastewater treatment plants (WWTPs). In those bioreactors, AOB within the Nitrosomonas europaea, N. oligotropha, N.-like, and Nitrosospira lineages were commonly found, while AOB within the N. communis, N. marina, and N. cryotolerans lineages were rarely detected in the samples. The AOB community structures were different in the bioreactors: AOB within the N. oligotropha lineage were the major microorganisms in the Pohang, the Palo Alto, and the Marshall WWTPs, while AOB within the N. europaea lineage were dominant in the Nine Springs WWTP. The correlations between the AOB community compositions of the wastewater treatment bioreactors and their operational (HRT, SRT, and MLSS) and environmental conditions (temperature, pH, COD, $NH_3$, and $NO_3{^-}$) were evaluated using a multivariate statistical analysis called the Redundancy Analysis (RDA). As a result, COD and $NO_3{^-}$ concentrations in the bioreactors were the statistically significant variables influencing the AOB community structures in the wastewater treatment bioreactors.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.977-981
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• 2006

본 연구는 오산천 하천환경정비로 인하여 저서성 대형무척추동물의 군집변화에 미치는 영향을 파악하기 위하여 2002년 6월부터 2005년 11월까지 5개지점을 선정하여 조사를 실시하였다. 조사기간 중 출현한 저서성 대형무척추동물은 총 4문 7강 16목 38과 81종이었으며, 년도별로는 2002년에는 총 55종이 출현하였으나, 2004년에는 36종으로 종수가 급감하였다. ESB에 따른 군집의 생태점수는 2003년도에 45.4에서 2004년도에는 21.7로 낮아졌다가 2005년도에는 31.2로 높아졌다. 이는 하천환경정비공사로 일시적인 교란을 일으켜 저서성 대형무척추동물의 군집변화에 영향을 미친 것으로 사료된다. 종조성의 변화로는 상류부의 경우 환경정비공사 완료 후 생태계안정화와 추이대가 복원되면서 1급수 지표종인 플라나리아(Dugesia japonica)와 옆새우(Gammarus sp.)가 출현하여 다양한 군집을 형성하고 있었다. 하류의 경우는 군집의 종조성이 빈약하지만 공사가 마무리 단계에 들어가면서 수서생물의 서식처가 안정화되고 있는 것으로 사료된다. 이처럼 저서성 대형무척추동물의 서식에 영향을 주는 하상의 물리적 구조와 이와 연관된 유기물 퇴적층과 토사 퇴적층에 대한 관리가 필요하며, 이를 통하여 하도특성에 맞는 안정된 군집구조가 형성될 수 있도록 대체서식처를 하천환경정비계획 수립 시 고려하여야 한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.487-487
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• 2023

농업 분야에서 미생물은 영양분 가용화, 유기물 분해 등 토양 영양분 공급에 중요한 역할을 하며, 토양 건강성 증진, 식량 안보 및 식품 건강 면에서 많은 활용 가능성을 지니고 있다. 최근 유역 환경 건강성, 생물 다양성 보존, 효율적인 고품질 농산물 생산에 대한 관심이 커져, 지속 가능한 농업 중 하나인 유기농업과 관행농업 토양의 이화학적 및 생물학적 특성에 관한 비교 연구가 진행되고 있다. 미생물은 지속 가능한 농업 발전의 중요한 요소 중 하나로써, 미생물 다양성이 풍부할수록 토양 비옥도, 작물 성장 면에서 긍정적인 영향을 미친다고 알려져 있다. 본 연구는 이에 대한 기초 데이터를 제공하기 위해 논 경작지를 대상으로 유기 및 관행농업 토양의 미생물 군집조성과 Alpha diversity analysis(Chao1, Shannon, Simpson index)을 통해 비교하였다. 경기도 양평군에서 유기 및 관행 논 지역을 각각 1지점씩 선정하였으며, 8월부터 11월까지 총 4회 현장 조사를 진행하였다. 미생물 분석은 차세대염기서열분석을 실시하였으며, bacteria는 16S rRNA V3-4 영역, fungi는 ITS 3-4 영역을 sequencing 하였다. 미생물 군집조성은 문수준에서는 큰 차이가 없었으나, 속수준에서는 fungi 군집조성에 차이를 보였다. 예로 Ustilaginoidea 속은 관행 논 토양에서만 발견되었으며, 벼 이삭누룩병을 일으키는 병원균으로 과도한 질소 비료 시비가 원인으로 추정된다. 종 다양성은 bacteria diversity의 경우 관행 논 토양에서 높게 측정되는 반면, fungi diversity의 경우 유기 논 토양에서 높게 측정되었다. 결론적으로 체계적인 시비 관리 통해 미생물 군집은 조절될 수 있으며, 관행농업은 적절한 시비를 통해 토양 건강성 및 식품 건강성 면에서 유기농업과 비슷한 효과를 보여줄 가능성이 있다고 판단된다.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.304-314
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• 2013

BACKGROUND: Ecological functions of irrigation ponds were well known fact that important for biodiversity conservation in agricultural ecosystems. However, many irrigation ponds were destructed with changes of agricultural environment. The objective of this study is to appreciate the importance of ecological functions of irrigation pond. Furthermore, it presented to useful information for restorations of irrigation pond from analyses of correlations between benthic macroinvertebrate communities and locational factors of irrigation ponds. METHODS AND RESULTS: Benthic macroinvertebrate sampling was conducted from 2010 to 2012 at 15 study ponds. Comparisons of benthic macroinvertebrates diversity approached species richness and density, and statistical analyses were performed using independent t-test. A total of 131 species / 137,118 individuals of benthic macroinvertebrates were recorded during study period. Dominant taxa of benthic macroinvertebrates included Coleoptera, Hemiptera, and Odonata. Generally, benthic macroinvertebrate diversity in mountain region and existing ponds were showed higher than open field and created ponds, respectively. DCA ordination showed that benthic macroinvertebrate community was most correlated with locational characteristics of irrigation pond, and it correlated with bank type and age of pond. CONCLUSION(S): In conclusions, in order to restore ecological irrigation pond, it is necessary to consider environmental factors such as locational characteristics and bank types.

• Korean Journal of Environment and Ecology
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• v.11 no.1
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• pp.111-125
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• 1997

To investigate the climax forest structure and to construct the ecological basic data, forty nine plots were set up and surveyed in Mt. Minjuji, Chungchongpukdo. According to the analysis of classification by TWINSPAN, the community was divided by seven groups of Pinus densiflora-Carpinus laxiflora-Quercus serrata(community I), Q. mongolica-Q. serrata-Platycarya strobilacea(community II), Q. mongolica(community III), Fraxinus mandshurica-Acer mono(community IV), Cornus controversa-F. mandshurica(community V), F. mandshurica-Carpinus cordata(community VI), and F. mandshurica-C. laxiflora(community VII). In the results of the analysis of species structure, similarity, diversity and DBH, except for community I~III, it was founede out broadleaves-mixed-climax forest. Constructed basic data will be applied to sustainable development such as ecotourism, nature trail etc.

• Korean Journal of Environment and Ecology
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• v.4 no.1
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• pp.1-15
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• 1990

To investigate the actual vegetation in Sokri mountain area, which consists of Sokri Mt. National Park, forest communities were classified by phytosocialogical analysis according to species composition and physiognomy. Actual vegetation map was drawn on the basis of classified forest communities. The forest communities in Mt. Sokri were classified as follows : 1. Pinus densiflora community 1) P. densiflora-Rhododedron mucronulatum subcommunity 2) P. densiflora-Rhododendron schippenbachii subcomminity 3) P. densiflora-Lespedeza maximowiczii subcommunity 4) P. densiflora-Sasa borealis subcommunity 2. P. densiflora-Quercus serrata community 3. P. densiflora-Q. variabilis community 4. Quercus serrata community 5. Q. serrata-Q. variabilis community 6. Carpinus laxiflora community 7. Quercus mongolica community 1) Typical subcommunity 2) Q. mongolica-Lespedeza maximowiczii subcommunity 3) Q. mongolica-Rhododendron schlippenbachii subcommunity 8. Fraxinus rhynchophylla community 9. Symplocos chinensis for. pilosa community 10. Quercus variabilis community

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.3
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• pp.117-124
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• 2011

Many studies of the phytoplankton community structure have been conducted using the CHEMTAX program on the basis of the photosynthetic pigment concentrations measured by a HPLC (High-Performance Liquid Chromatography) technique. The CHEMTAX program determines the contribution of each phytoplankton class to total phytoplankton biomass (chlorophyll a) based on the ratios of marker pigment to chlorophyll a of phytoplankton group. In this study, the marker pigment/chlorophyll a ratios were investigated in phytoplankton species isolated from marine waters around the Korean peninsula. These results were used as the input pigment ratios of the CHEMTAX program to investigate phytoplankton community structure in Korean coastal waters (Yeoja and Gamak Bay). There were significant differences in the ratios of marker pigment to chlorophyll a among the different species within the same algal class. There was a significant difference between the values of our ratios and the previously used ratios in other regions of the world. When phytoplankton community composition was calculated using our initial ratios in Yeoja and Gamak Bay, our results were significantly different from the results calculated on the basis of initial ratios of marker pigment in phytoplankton suggested in other marine waters. The estimates of the contributions of the major algal groups (bacillariophyceae and dinophytes) to total chlorophyll a varied within 5% depending on the initial ratios chosen. The variations of estimates for the pico- and nanoplankton (cyanophytes and prasinophytes), which have relatively low contributions to total chlorophyll a, were higher than those for major algal group. Although the HPLC-pigment measurements combined with CHEMTAX analysis are useful for identifying and qualifying phytoplankton community structure, further researches for the pigment ratios of the dominant phytoplankton species presenting in a given area are also needed.

• Korean Journal of Plant Resources
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• v.33 no.1
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• pp.1-14
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• 2020

This study was conducted to analyze community structure and species composition of Pinus densiflora for. erecta Stand in Mt. Cheonchuk (653 m). Field survey was carried out from June to September in 2013. 74 plots (20×20 m) were set up, 5 herb layer plots (3×3 m) were constructed for each plot, and there, Diameter at Breast Heigh t(DBH), height, environmental factor, annual growth were measured. Vascular plants were surveyed as following; 66 family, 165 genus, 211 species, 2 sub species, 29 variety, 6 form 248 taxa. Results of cluster analysis for P. densiflora for. erecta forest, 3 communities were divided into; Quercus mongolica (P-1), Quercus variabilis (P-2) and Quercus aliena-Stephanandra incisa (P-3). There were significant environmental factors that organic layer, annual growth, CEC, total total nitrogen, organic matter and pH for each community. As a result of DCA, P-1 and P-2 were distributed large range of environmental factors but relatively limited in P-3. Distributions of herb layer were affected by sand, cation exchange capacity, silt and total nitrogen. Results of MRPP test for herb layer communities, it was significantly analyzed (A=0.003, P<0.008). Species diversity index was highly recorded in P-3 and influenced by cation exchange capacity, total nitrogen, annual growth in consequence of NMS analysis.

• Journal of the Mineralogical Society of Korea
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• v.13 no.4
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• pp.205-220
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• 2000

북동태평양 C-C지역의 우리나라 광구에서 산출되는 망간단괴의 내부조직을 크게 주상조직 층상대, 첨상조직 층상대, 첨상조직 괴상대, 첨상조직 다공질대 및 괴상조직 괴상대로 구분하였다. 주상조직 층상대에서는 버나다이트(vernadite)가 가장 우세하게 산출되며, 첨상조직 층상대에서는 부서라이크(buserite)가 함께 산출된다. 첨상조직 괴상대는 부서라이트의 산출이 두드러지며, 부분적으로 토도로카이트(todorokite)가 수반된다. 첨상조직 다공질대는 첨상체 또는 구상체로 이루어지며 부분적으로 괴상조직으로 교대되는데 주로 토도로카이트와 부서라이트로 구성되어 있다. 괴상조직을 갖는 괴상대에서는 토도로카이트와 버네사이트(birnessite)가 부서라이트와 함께 산출된다. 각 조직대별로 미세조직을 이루는 엽리들에 대해 전자현미분석을 실시하였다. 엽리의 화학조성을 구성하는 요인은 상관계수 군집분석에 의해 Mn-K의 Mn군, Cu-Ni-Zn-Mg(Ca-Na)의 Cu-Ni-Mg군 Fe-Co-Ti(Ca-P)의 Fe군과 Si-Al의 Si군 등 네 개군으로 구분된다. 각 조직대는 세 개 또는 네 개의 군으로 구성되며 이들 각군은 단괴에서 산출되는 광물과 밀접한 관계를 가진다. Mn군은 토도로카이트, Cu-Ni-Mg군은 부서라이트, Fe군은 함코발트수산화철광물, 그리고 Si군은 규산염광물에서 주로 기인하는 것으로 생각된다. 엽리의 화학조성은 이들 광물의 조합과 구성광물의 화학조성에 따라 지배되고 한 조직대내에서도 여러종류의 조합을 보이는데 이는 각 조직대의 엽리들의 성인과 밀접한 관련이 있는 것으로 생각된다.